Exactly what happened to me but I was stuck on Radio 1, and I didn't fancy that all the way back to Surrey.
I was on the threshold of disconnecting the 12v battery under instruction from Eden Vauxhall in Exeter, (I was in Cornwall at the time) , as I'd tried everything I could think of including resetting to factory settings. I left it to charge overnight, and it was all back to normal next day.
If a full charge doesn't do it, then working out which fuse it is on might be better than disconnecting the battery.
The other point is that this glitch and a handful of others in the first 6 months all went away after the software updates were all applied. Makes me wonder if some updates may yet to be applied.
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